Effects of the ephedra alkaloid methylephedrine on the basal evoked potential transportation and the long-term potentiation (LTP) in the rat hippocampal dentate granule cells in vivo

Objective The effect of the ephedra/ephedrine alkaloid methylephedrine(dl-methylephedrine hydrochloride for testing in this paper)on cognitive related synaptic plasticity was investigated by recording extracellular field evoked potentials and its LTP in hippocampal dentate granule cells in urethane-anaesthetized rats in vivo.Methods Single pathway recording of evoked field potentials was made from the dentate granule cells of hippocampal hemisphere in response to stimulation of the ipsilateral medial perforant path(MPP).Two parameters,the amplitude of population spike(PS amplitude)and the latency of the PS,were employed to evaluate the effects of drug on the overall changes in cellular responses.Results The present study show that methylephedrine 90 mg·kg-1 intraperitoneally,about 1/3 LD50,could increase the latency of the PS in hippocampal dentate granule cells by constant single stimulation of the MPP as the basal ransportation.However,the 30 mg·kg-1 and 10 mg·kg-1 dosage had no effect on the latency,and there are no influences of PS amplitude for all examinational groups.The methylephedrine 90 mg·kg-1 group significant enhanced the development of amplitude LTP in hippocampal dentate granule cells that induced by 60 Hz,60 pulses conditional tetanus in medial perforant path area.Also,the 30 mg·kg-1 group can promoted the maintenance of LTP induced by this tetanus,but no promotion on PS amplitude LTP appeared in this dosage and no any changes been found in 10 mg·kg-1 dosage group.Conclusions The ephedra/ephedrine alkaloid methylephedrine can modulate the synaptic plasticity in the lateral perforant path.A possible mechanism of methylephedrine on hippocampal LTP is been discussed.

Ephedra Herb extract ameliorates adriamycin-induced nephrotic syndrome in rats via the CAMKK2/AMPK/mTOR signaling pathway

This study aimed to investigate the effect and mechanisms of Ephedra Herb(EH)extract on adriamycin-induced nephrotic syndrome(NS),providing an experimental basis for the clinical treatment of NS.Hematoxylin and eosin staining,creatinine,urea nitrogen,and kidn injury molecule-1 were used to evaluate the activities of EH extract on renal function.The levels of inflammatory factors and oxidative stress were detected by kits.The levels of reactive oxygen species,immune cells,and apoptosis were measured by flow cytometry.A network pharmacological approach was used to predict the potential targets and mechanisms of EH extract in the treatment of NS.The protein levels of apoptosis-related proteins and CAMKK2,p-CAMKK2,AMPK,p-AMPK,mTOR and p-mTOR in the kidneys were detected by Western blot.The effective material basis of EH extract was screened by MTT assay.The AMPK pathway inhibitor(compound C,CC)was added to investigate the effect of the potent material basis on adriamycin-induced cell injury.EH extract significantly improved renal injury and relieve inflammation,oxidative stress,and apoptosis in rats.Network pharmacology and Western blot results showed that the effect of EH extract on NS may be associated with the CAMKK2/AMPK/mTOR signaling pathway.Moreover,methylephedrine significantly ameliorated adriamycin-induced NRK-52e cell injury.Methylephedrine also significantly improved the phosphorylation of AMPK and mTOR,which were blocked by CC.In sum,EH extract may ameliorate renal injury via the CAMKK2/AMPK/mTOR signaling pathway.Moreover,methylephedrine may be one of the material bases of EH extract.